INTRODUCTION
A small number of drugs can rarely result in cutaneous
pigmentation,1-8 the most common of which is
minocycline.2,4,9-15 Skin affected by minocycline pigmentation
typically takes on a slate-gray appearance. Histopathologic
examination of skin biopsies taken from affected
sites reveals brown and/or black granules in the dermis, both
within and outside of dermal macrophages.16,17 Pigment accumulates
around dermal blood vessels and in the vicinity of
eccrine sweat glands.17 Typically, drug-induced pigmentation
occurs in sites of vascular leakage such as in the vicinity of
lower extremity spider veins or venous stasis, within facial
vessels resulting from sun-damage such as within rosacea,
and in sites of bruising or trauma.1,2,4,10,18-20 In addition to cutaneous
involvement, other organ systems can be affected such
as the thyroid,21-24 blood vessels,25,26 bone,9,27cartilage,9,11,27
and other tissue.28-32 Here we report cutaneous minocycline
pigmentation following carbon dioxide laser resurfacing of
the upper lip, presenting as presumed melasma or post-inflammatory
hyperpigmentation.
REPORT OF A CASE
A 64 year-old woman with Fitzpatrick skin type I presented
with a 5-year history of pigmentation on only her upper-lip.
She had a history of photodamage as evidenced by rhytides,
which were especially deep on her upper lip. The patient had
acne since her teenage years and had been on a course of
isotretinoin for cystic acne for a period of 6 months, 25 years
prior to her presentation to us. She had subsequently been
taking minocycline 100 mg daily for 4 years starting 8 years
prior to presenting here, and ending 4 years prior to coming
to us. She had non-fractionated, carbon dioxide laser
resurfacing of only her upper lip approximately 5 years ago,
and approximately 2 months later noticed discoloration of
her upper lip, which she attributed to sun-exposure. Her dermatologist
referred her here for possible laser treatment of
the hyperpigmentation of her upper lip, which was thought
to be sun-induced melasma or post-inflammatory hyperpigmentation,
and which persisted since her laser procedure.
Subsequent examination with a cross-polarizing, magnifying
headlamp (v600, Syris Scientific, Gray, ME) revealed the
pigmentation to be slate-gray in color and located sub-epidermally,
consistent with classic drug-induced pigmentation,
most commonly observed due to ingestion of minocycline.
The patient had been taking minocycline for 3 years prior
to her resurfacing procedure and 1 year following it. Upon
presentation, the patient reported that the pigment had been
stable for approximately 5 years, and involved only the upper
lip (Figure 1a). Numerous topical preparations including
alpha-hydroxy acids and hydroquinone were applied to the
affected area with no improvement. A punch biopsy of the
pigmented area was obtained and demonstrated Fontana
staining in the epidermis in normal amounts, within some
dermal macrophages, and surrounding blood vessels. Some
dermal macrophages stained positively for iron (Figure 2a
and b). Taken together with the clinical findings, these changes
are consistent with drug-induced pigmentation.
After test spots demonstrating immediate pigment whitening
upon laser impact, the patient’s entire lip was treated
using the 1064 nm, Q-switched neodymium: yttrium, aluminum
garnet (Nd:YAG) laser (Con-Bio RevLite SI, Cynosure,
Inc., Westford, MA) using a fluence of 6.5 J/cm2 and a beam
diameter or 5.0 mm. The laser used in the current study has a
setting that selects the maximally available spot size with the
